Enhancing carbon sequestration in peatlands using exogenous phenolic inhibitors

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  • Adel Alshehri

Abstract

Northern hemisphere peatlands store approximately 455 Pg of organic carbon (C) and are an important component of the global C cycle, currently acting as sinks for atmospheric C, despite peatlands only covering 3% of the planet’s surface. The presence of phenolic compounds in the peatlands allows these stocks to accumulate, by slowing down the process of decomposition to below that of photosynthetic production. Phenolic inhibitors are abundant due to the unique properties in waterlogged peatlands, which have the ability to suppress phenol oxidase activity, which is among the few enzymes capable of degrading phenolic compound inhibitors. This permits accumulation of phenolic compounds, which, in turn, prevents hydrolase enzymes from breaking down organic matter and thus promoting sequestration of C in peatlands. This mechanism has been described as the “enzymic latch” and leads to carbon sequestration in peat. It is noteworthy that human carbon emissions, which exceed 8 Pg per year leading to global warming, can turn these wetlands from carbon sinks into important sources of greenhouse gases, namely carbon dioxide (CO2) and methane (CH4). To help prevent further climate change, this study examined whether manipulation of the enzymic latch might reduce the rate of decomposition by increasing the abundance of phenolic inhibitors in peat soil and thus reducing the rate of carbon release into the atmosphere. The study showed that inhibitory phenolic additions may have an effect on carbon sequestration in peatlands in the form of supplementary wood chips, which have proven promote carbon storage in peat matrices. The results also demonstrated the ability of waste materials such as crude oil to suppress CO2 release that requires further study. Low molecular weight phenolic inhibitors may be more potent than high molecular weight in terms of effect on suppressing enzymic decomposition.

Details

Original languageEnglish
Awarding Institution
Supervisors/Advisors
Thesis sponsors
  • Government of Saudi Arabia
Award dateJan 2017